1. Field of the Invention
This invention relates to a composite energy producing gas turbine system which, in addition to providing shaft power normally associated with gas turbines, provides heat energy for use as process heat. In another embodiment, the apparatus and process of this invention provides shaft power, process heat and cooling output from the system. The process heat and the cooling may be provided at pre-selected temperatures resulting in very high energy efficient utilization of the system. Industrial complexes requiring electricity, heat and cooling functions, each of which are normally supplied by a different device, may utilize a single composite energy producing gas turbine system according to this invention to provide high combined fuel economy of the industrial plant.
2. Description of the Prior Art
Utilization of conventional gas turbines for shaft power output functions, such as electrical generation, are well known in the art. U.S. Pat. No. 3,867,811 teaches inter-cooling and regeneration for power modulation of a gas turbine by variation of the inlet temperature of the working fluid to the compressor. For the purpose of inter-cooling, the compressor is split into two stages and the temperature is reduced between stages in a heat exchanger. This reduces the power required to drive the compressor and thereby increases the net power of the engine. However, fuel economy is decreased due to the loss of heat. The U.S. Pat. No. 3,867,811 teaches enhancement of the effect of inter-cooling by use of a low temperature refrigerant. The U.S. Pat. No. 3,867,811 also teaches utilization of two turbine sections and passing working fluid from the first turbine into a heat exchanger where the working fluid is preheated as it passes from the compressor discharge to a heater, thereby replacing heat lost by inter-cooling. By these features, the internal thermodynamics of the gas turbine system, itself, are improved, but overall system energy requirements are increased.